Relevant devices to which this disclosure finds application include MEMS electrostatic actuators (also known as capacitive actuators) which have a first electrode (bottom plate) fixed to a substrate and a second electrode (top plate) supported in elevated position above the substrate for selective controllable movement toward and away from the first electrode. A voltage applied between the electrodes creates an attractive force, drawing the electrodes together. Applying an opposing voltage and/or a mechanical spring action creates a restorative force, driving the electrodes apart. A thin layer of dielectric material applied over the first electrode prevents shorting.
Additional background is described in Gupta et al. application Ser. No. 13/614,936 “MEMS ELECTROSTATIC ACTUATOR” filed Sep. 13, 2013, the entirety of which is incorporated by reference herein.